1. Field of the Invention
This invention relates to an improved anchoring arrangement for use in conjunction with cavity walls. More particularly, the invention relates to construction accessory devices, namely, veneer ties with a compressed interconnection junction and a thermally isolated sealing anchoring system for insulated cavity walls. The invention is applicable to structures having an outer wythe of brick or stone facing in combination with an inner wythe of either masonry block or dry wall construction with optional insulation thereon.
2. Description of the Prior Art
In the past, investigations relating to the effects of various forces, particularly lateral forces, upon brick veneer masonry construction demonstrated the advantages of having high-strength wire anchoring components embedded in the bed joints of anchored veneer walls, such as facing brick or stone veneer. Anchors and ties are generally placed in one of the following five categories: corrugated; sheet metal; wire; two-piece adjustable; or joint reinforcing. The present invention has a focus on wire formative veneer ties.
Prior tests have shown that failure of anchoring systems frequently occurs at the juncture between the veneer tie and the receptor portion of the wall anchor. This invention addresses the need for a high-strength veneer tie interconnection suitable for use with both a masonry block and dry wall construction and provides a tie-to-receptor connection.
In the late 1980's, surface-mounted wall anchors were developed by Hohmann & Barnard, Inc., now a MiTek-Berkshire Hathaway company, patented under U.S. Pat. No. 4,598,518 ('518). The invention was commercialized under trademarks DW-10®, DW-10-X®, and DW-10-HS®. These widely accepted building specialty products were designed primarily for drywall construction, but were also used with masonry backup walls. For seismic applications, it was common practice to use these wall anchors as part of the DW-10 Seismiclip® interlock system which added a Byna-Tie® wire formative, a Seismiclip® snap-in device—described in U.S. Pat. No. 4,875,319 ('319), and a continuous wire reinforcement.
In the dry wall application, the surface-mounted wall anchor of the above-described system has pronged legs that pierce the insulation and the wallboard and rest against the metal stud to provide mechanical stability in a four-point landing arrangement. The vertical slot of the wall anchor enables the mason to have the wire tie adjustably positioned along a pathway of up to 3.625-inch (max). The interlock system served well and received high scores in testing and engineering evaluations which examined the effects of various forces, particularly lateral forces, upon brick veneer masonry construction. However, under certain conditions, the system did not sufficiently maintain the integrity of the insulation.
The engineering evaluations further described the advantages of having a continuous wire embedded in the mortar joint of anchored veneer wythes. The seismic aspects of these investigations were reported in the inventor's '319 patent. Besides earthquake protection, the failure of several high-rise buildings to withstand wind and other lateral forces resulted in the incorporation of a continuous wire reinforcement requirement in the Uniform Building Code provisions. The use of a continuous wire in masonry veneer walls has also been found to provide protection against problems arising from thermal expansion and contraction and to improve the uniformity of the distribution of lateral forces in the structure.
Shortly after the introduction of the pronged wall anchor, a seismic veneer anchor, which incorporated an L-shaped backplate, was introduced. This was formed from either 12- or 14-gage sheetmetal and provided horizontally disposed openings in the arms thereof for pintle legs of the veneer anchor. In general, the pintle-receiving sheetmetal version of the Seismiclip® interlock system served well, but in addition to the insulation integrity problem, installations were hampered by mortar buildup interfering with pintle leg insertion.
In the 1980's, an anchor for masonry veneer walls was developed and described in U.S. Pat. No. 4,764,069 by Reinwall et al., which patent is an improvement of the masonry veneer anchor of Lopez, U.S. Pat. No. 4,473,984. Here the anchors are keyed to elements that are installed using power-rotated drivers to deposit a mounting stud in a cementitious or masonry backup wall. Fittings are then attached to the stud which include an elongated eye and a wire tie therethrough for disposition in a bed joint of the outer wythe. It is instructive to note that pin-point loading—that is forces concentrated at substantially a single point—developed from this design configuration. Upon experiencing lateral forces over time, this resulted in the loosening of the stud.
the past, the use of wire formatives have been limited by the mortar layer thickness which, in turn are dictated either by the new building specifications or by pre-existing conditions, e.g. matching during renovations or additions to the existing mortar layer thickness. While arguments have been made for increasing the number of the fine-wire anchors per unit area of the facing layer, architects and architectural engineers have favored wire formative anchors of sturdier wire.
Contractors found that heavy wire anchors, with diameters approaching the mortar layer height specification, frequently result in misalignment. This led to the low-profile wall anchors of the inventors hereof as described in U.S. Pat. No. 6,279,283. However, the above-described technology did not fully address the adaption thereof to insulated inner wythes utilizing stabilized stud-type devices.
Another prior art development occurred shortly after that of Reinwall/Lopez when Hatzinikolas and Pacholok of Fero Holding Ltd. introduced their sheetmetal masonry connector for a cavity wall. This device is described in U.S. Pat. Nos. 5,392,581 and 4,869,043. Here a sheetmetal plate connects to the side of a dry wall column and protrudes through the insulation into the cavity. A wire tie is threaded through a slot in the leading edge of the plate capturing an insulative plate thereunder and extending into a bed joint of the veneer. The underlying sheetmetal plate is highly thermally conductive, and the '581 patent describes lowering the thermal conductivity by foraminously structuring the plate. However, as there is no thermal break or barrier, a concomitant loss of the insulative integrity results.
The construction of a steel-framed inner wythe of a commercial building, to which masonry veneer is attached, uses steel studs with insulation installed outboard of the steel stud framing. Steel anchors and ties attach the outer wythe to the inner wythe by screwing or bolting an anchor to a steel stud. Although steel offers many benefits, it does not provide the high insulation efficiency of timber framing and can cause the effective R-value of fiberglass batt insulation between the steel studs to fall 50 to 60%.
Steel is an extremely good conductor of heat. The use of steel anchors attached to steel framing draws heat from the inside of a building through the exterior sheathing and insulation, towards the exterior of the masonry wall. In order to maintain high insulation values, a thermal break or barrier is needed between the steel framing and the outer wythe. This is achieved by the present invention through the use of high-strength polymeric components which have low thermal conductivity.
To ensure proper insulative properties in cavity walls, building requirements continue to increase the required amount of insulation. Exemplary of the public sector building specification is that of the Energy Code Requirement, Boston, Mass. (See Chapter 13 of 780 CMR, Seventh Edition). This Code sets forth insulation R-values well in excess of prior editions and evokes an engineering response opting for thicker insulation and correspondingly larger cavities.
As insulation became thicker, the tearing of insulation during installation of the pronged DW-10X wall anchor, see supra, became more prevalent. This occurred as the installer would fully insert one side of the wall anchor before seating the other side. The tearing would occur during the arcuate path of the insertion of the second leg. The gapping caused in the insulation permitted air and moisture to infiltrate through the insulation along the pathway formed by the tear. While the gapping was largely resolved by placing a self-sealing, dual-barrier polymeric membrane at the site of the legs and the mounting hardware, with increasing thickness in insulation, this patchwork became less desirable. The improvements hereinbelow in surface mounted wall anchors look toward greater retention of insulation integrity and less reliance on a patch.
The high-strength veneer tie of this invention is specially configured to prevent veneer tie pullout. The configured tie restricts movement in all directions, ensuring a high-strength connection and transfer of forces between the veneer and the backup wall. The wire formative insertion portion for disposition within the outer wythe, is optionally compressively reduced in height by the cold-working thereof and compressively patterned to securely hold to the mortar joint and increase the veneer tie strength. The close control of overall heights permits the mortar of the bed joints to flow over and about the veneer ties. Because the wire formative hereof employ extra strong material and benefit from the cold-working of the metal alloys, the high-span anchoring system meets the unusual requirements demanded in current building structures. Reinforcement wires are included to form seismic constructs.
The following patents are believed to be relevant and are disclosed as being known to the inventor hereof:
U.S. Pat. No.InventorIssue Date3,377,764StorchApr. 16, 19684,021,990SchwalbergMay 10, 19774,373,314AllanFeb. 15, 19834,473,984LopezOct. 2, 19844,598,518HohmannJul. 8, 19864,869,038CataniSep. 26, 19894,875,319HohmannOct. 24, 19895,392,581Hatzinikolas et al.Feb. 28, 19955,454,200HohmannOct. 3, 19955,456,052Anderson et al.Oct. 10, 19955,816,008HohmannOct. 15, 19986,209,281RiceApr. 3, 20016,279,283Hohmann et al.Aug. 28, 20016,668,505Hohmann et al.Dec. 30, 20036,789,365Hohmann et al.Sep. 14, 20046,851,239Hohmann et al.Feb. 8, 20057,017,318HohmannMar. 28, 20067,325,366HohmannFeb. 5, 20087,415,803BronnerAug. 26, 2008
U.S. Pat. No. 3,377,764—Storch—Issued Apr. 16, 1968 Discloses a bent wire, tie-type anchor for embedment in a facing exterior wythe engaging with a loop attached to a straight wire run in a backup interior wythe.
U.S. Pat. No. 4,021,990—Schwalberg—Issued May 10, 1977 Discloses a dry wall construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheetmetal anchor. Like Storch '764, the wall tie is embedded in the exterior wythe and is not attached to a straight wire run.
U.S. Pat. No. 4,373,314—Allan—Issued Feb. 15, 1983 Discloses a vertical angle iron with one leg adapted for attachment to a stud; and the other having elongated slots to accommodate wall ties. Insulation is applied between projecting vertical legs of adjacent angle irons with slots being spaced away from the stud to avoid the insulation.
U.S. Pat. No. 4,473,984—Lopez—Issued Oct. 2, 1984 Discloses a curtain-wall masonry anchor system wherein a wall tie is attached to the inner wythe by a self-tapping screw to a metal stud and to the outer wythe by embedment in a corresponding bed joint. The stud is applied through a hole cut into the insulation.
U.S. Pat. No. 4,598,518—Hohmann—Issued Jul. 7, 1986 Discloses a dry wall construction system with wallboard attached to the face of studs which, in turn, are attached to an inner masonry wythe. Insulation is disposed between the webs of adjacent studs.
U.S. Pat. No. 4,869,038—Catani—Issued Sep. 26, 1989 Discloses a veneer wall anchor system having in the interior wythe a truss-type anchor, similar to Hala et al. '226 supra, but with horizontal sheetmetal extensions. The extensions are interlocked with bent wire pintle-type wall ties that are embedded within the exterior wythe.
U.S. Pat. No. 4,875,319—Hohmann—Issued Oct. 24, 1989 Discloses a seismic construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheetmetal anchor. The wall tie is distinguished over that of Schwalberg '990 and is clipped onto a straight wire run.
U.S. Pat. No. 5,454,200—Hohmann—Issued Oct. 3, 1995 Discloses a facing anchor with straight wire run mounted along the exterior wythe to receive the open end of wire wall tie with each leg thereof being placed adjacent one side of reinforcement wire. As the eye wires hereof have scaled eyelets or loops and the open ends of the wall ties are sealed in the joints of the exterior wythes, a positive interengagement results.
U.S. Pat. No. 5,392,581—Hatzinikolas et al.—Issued Feb. 28, 1995 Discloses a cavity-wall anchor having a conventional tie wire for mounting in the brick veneer and an L-shaped sheetmetal bracket for mounting vertically between side-by-side blocks and horizontally atop a course of blocks. The bracket has a slit which is vertically disposed and protrudes into the cavity. The slit provides for a vertically adjustable anchor.
U.S. Pat. No. 5,456,052—Anderson et al.—Issued Oct. 10, 1995 Discloses a two-part masonry brick tie, the first part being designed to be installed in the inner wythe and then, later when the brick veneer is erected to be interconnected by the second part. Both parts are constructed from sheetmetal and are arranged on substantially the same horizontal plane.
U.S. Pat. No. 5,816,008—Hohmann—Issued Oct. 15, 1998 Discloses a brick veneer anchor primarily for use with a cavity wall with a drywall inner wythe. The device combines an L-shaped plate for mounting on the metal stud of the drywall and extending into the cavity with a T-head bent stay. After interengagement with the L-shaped plate the free end of the bent stay is embedded in the corresponding bed joint of the veneer.
U.S. Pat. No. 6,209,281—Rice—Issued Apr. 3, 2001 Discloses a masonry anchor having a conventional tie wire for mounting in the brick veneer and sheetmetal bracket for mounting on the metal-stud-supported drywall. The bracket has a slit which is vertically disposed when the bracket is mounted on the metal stud and, in application, protrudes through the drywall into the cavity. The slit provides for a vertically adjustable anchor.
U.S. Pat. No. 6,279,283—Hohmann et al.—Issued Aug. 28, 2001 Discloses a low-profile wall tie primarily for use in renovation construction where in order to match existing mortar height in the facing wythe a compressed wall tie is embedded in the bed joint of the brick veneer.
U.S. Pat. No. 7,415,803—Bronner—Issued Aug. 26, 2008 Discloses a double-wingnut anchor system and method for connecting an anchor shaft extending from the back up wall to a wire tie extending from a veneer wall. The wingnut houses the wire tie legs and is independently rotatable to obtain the desired angular position.
U.S. Pat. No. 6,668,505—Hohmann et al.—Issued Dec. 30, 2003 Discloses high-span and high-strength anchors and reinforcement devices for cavity walls combined with interlocking veneer ties are described which utilize reinforcing wire and wire formatives to form facing anchors, truss or ladder reinforcements, and wall anchors providing wire-to-wire connections therebetween.
U.S. Pat. No. 6,789,365—Hohmann et al.—Issued Sep. 14, 2004 Discloses side-welded anchor and reinforcement devices for a cavity wall. The devices are combined with interlocking veneer anchors, and with reinforcements to form unique anchoring systems. The components of each system are structured from reinforcing wire and wire formatives.
U.S. Pat. No. 6,851,239—Hohmann et al.—Issued Feb. 8, 2005 Discloses a high-span anchoring system described for a cavity wall incorporating a wall reinforcement combined with a wall tie which together serve a wall construct having a larger-than-normal cavity. Further the various embodiments combine wire formatives which are compressively reduced in height by the cold-working thereof. Among the embodiments is a veneer anchoring system with a low-profile wall tie for use in a heavily insulated wall.
U.S. Pat. No. 7,017,318—Hohmann—Issued Mar. 28, 2006 Discloses an anchoring system with low-profile wall ties in which insertion portions of the wall anchor and the veneer anchor are compressively reduced in height.
U.S. Pat. No. 7,325,366—Hohmann—Issued Feb. 5, 2008 Discloses snap-in veneer ties for a seismic construction system in cooperation with low-profile, high-span wall anchors.
The present invention provides an advancement in anchoring systems. The use of polymeric components at key locations in the anchor provides thermal breaks between the highly conductive steel framing studs and the outer wythe. Further, the seal structure prevents moisture from infiltrating the insulation and cavity and provides an adjustable method of veneer tie attachment. This thermally-isolating anchor is combined with a configured compressed high-strength veneer tie that restricts veneer movement.
None of the above references provide the innovations of this invention. As will become clear in reviewing the disclosure which follows, the insulated cavity wall structures benefit from the recent developments described herein that lead to solving the problems of thermal isolation, of insulation and air/vapor barrier integrity, of high-span applications, of pin-point loading, and a high-strength veneer tie interconnection. This invention relates to an improved anchoring arrangement for use in conjunction with cavity walls having an inner wythe and an outer wythe and meets the heretofore unmet needs described above.